Reactivated Expression of MicroRNA-124 in Patients with Myelodysplastic Syndromes after Demethylating Therapy / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To explore the role of microRNA-124(miR-124) in the pathogenesis of myelodysplastic syndromes(MDS) through detecting the expression level of miR-124 in bone marrow mononuclear cells(MNC) of MDS patients before and after demethylating therapy with decitabine.</p><p><b>METHODS</b>The expression levels of miR-124 in the MNC of 35 MDS patients and 10 healthy donors were detected with stem-loop quantitative real time polymerase chain reaction assay.</p><p><b>RESULTS</b>The expression level of miR-124 was lower in MDS patients than that in healthy donors. The difference was not statistically significant between patients with low-risk MDS subtypes (RA and RCMD) and control, but statistically significant between patients with high-risk MDS subtypes (RAEB1, RAEB2 and CMML) and control. This study also proved that expression of miR-124 was reactivated in 7 out of 18 MDS patients after treatment with low dose decitabine.</p><p><b>CONCLUSION</b>The hypermethylation and silencing of miR-124 may be an important factor in the clonal transformation of MDS cells.</p>

Abnormal expression of microRNA-124 in patients with leukemia or myelodysplastic syndrome and its significance / 中国实验血液学杂志

This study was aimed to investigate the abnormal expression of microRNA-124 (miR-124) in bone marrow cells of patients with leukemia or myelodysplastic syndrome (MDS) and its significance. The relative expression levels of miR-124 in bone marrow mononuclear cells from 33 patients with newly diagnosed leukemia or MDS, and 10 normal donors (as controls) were detected by stem-loop fluorescence real-time quantitative RT-PCR. The methylation levels of miR-124 promoter were detected by quantitative methylation specific PCR in partial MDS samples. The results indicated that as compared with normal control, lower levels of miR-124 (≤ 1/3) were found in 2/18 of leukemia patients and in 5/15 of MDS patients (among them ≤ 1/4 in 3/15 MDS patients). No statistically significance difference was observed between leukemia patients and normal controls (P = 0.725). However the difference was statistically significant between MDS group and control group (P = 0.031). Furthermore, an elevated methylation level of miR-124 promoter region in some of MDS patients (7/11) was detected by using quantitative methylation-specific PCR. The expression level of miR-124 was related with methylation level of promoter region (R(2) = 0.339, P = 0.018). It is concluded that the expression of miR-124 in partial MDS patients is inhibited, which may be associated with the abnormal methylation of its promoter.

Expression of miR-21 in multiple myeloma and its clinical significance / 中国实验血液学杂志

This study was aimed to explore the expression of microRNA-21 (miR-21) in multiple myeloma (MM), and its correlation with plasma β2-microglobulin (β2-MG) and staging of MM by Durie-Salmon (D-S) classification. The expression level of miR-21 in bone marrow mono-nuclear cells (BMMNC) of 43 patients with MM and 20 healthy individuals was examined by real-time polymerase chain reaction (real-time PCR), and the correlations among the expression level of miR-21 and related clinical pathologic features, plasma β2-MG and staging of MM by D-S classification were analyzed. The results showed that the expression of miR-21 in BMMNC of MM patients was obviously higher than that in normal controls (P < 0.05). The expression of miR-21 in BMMNC of relapsed/refractory MM patients was obviously higher than that in newly diagnosed MM patients. The expression of miR-21 in MM patients decreased after chemical therapy, especially in effective group (P < 0.05), there was no significant change of miR-21 expression level in ineffective/progressive group before and after chemical therapy (P > 0.05). The expression of miR-21 was related with staging of MM and plasma β2-MG level. It is concluded that the expression levels of miR-21 in BMMNC of MM patients are significantly higher than in normal bone marrow, these data indicated that miR-21 may play an important role in the development of MM. Super expression of miR-21 is positively correlated with level of plasma β2-MG and staging of MM by D-S classification.

Expression of transcription factor LYL1 in leukemia and its possible role in leukemogenesis / 中华血液学杂志

<p><b>OBJECTIVE</b>To study the expression of transcription factor LYL1 in leukemia and its possible role in leukemogenesis.</p><p><b>METHODS</b>Fluorescence real time quantitative polymerase chain reaction was used to detect the expression levels of LYL1 in leukemias. Specific siRNA was used to silence the expression of LYL1 in K562 cells.</p><p><b>RESULTS</b>Compared to CD34 positive cells from normal bone marrow, the expression of LYL1 was significantly elevated in patients with acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL). LYL1 expression was higher in chronic myeloid leukemia (CML) in blastic crisis than that in chronic phase (7.831 vs 1.672, P < 0.01). LYL1 expression in AML in complete remission (CR) was down-regulated as compared with that of un-remission patients (1.400 vs 9.985, P < 0.01). Down-regulation of endogenous expression of LYL1 in K562 cells by a combination of three specific siRNA could inhibit cellular growth and clonogenicity to some extent.</p><p><b>CONCLUSION</b>Over-expression of LYL1 is highly associated with AML as well as ALL. RNA interference targeting specific oncogenes such as LYL1 is potentially useful in the treatment of hematological malignancies.</p>

Comparative proteomics research of apoptosis initiation induced by homoharringtonine in HL-60 cells / 中华血液学杂志

<p><b>OBJECTIVE</b>To study the related proteins of apoptosis initiation induced by homoharringtonine (HHT) in HL-60 cells.</p><p><b>METHODS</b>After establishment of an apoptosis initiation model induced by HHT in HL-60 cells, proteins of untreated and HHT treated HL-60 cells were extracted, and the two-dimensional polyacrylamide gel electrophoresis (2-DE) maps of the extracted proteins were established by using the immobilized pH gradient (IPG) two-dimensional electrophoresis respectively. The alteration protein spots were identified with assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS) and database searching.</p><p><b>RESULTS</b>Proteomics analysis showed that proteins including MHC class I antigen, calbindin D-28K, chloride channel protein 6, oncoprotein 18, zinc finger protein Helios and apoptosis inhibitor like protein 2 were involved in apoptosis initiation induced by HHT.</p><p><b>CONCLUSION</b>The present study might conduce to the researches of HL-60 cells carcinogenesis and pave the way to exploit drug precursor related to HHT and initiation of apoptosis in HL-60 cells.</p>